One of the things I like about Panama is the relatively small population of a little over 3.3 million. This rather small population is one of the reasons you don't see such blatant poverty that can be seen throughout most of Central American and Caribbean countries. Costa Rica is the only other country in the area that has been blessed with a rather small population and a manageable growth rate of about 1.3%. That is not to say there is no poverty here. But, even with the reported 40% living below the poverty level you don't see much of it because most are living in the interior on plots of land that provide a subsistence living. Panama also has a large indigenous population who for the most part live in that 40% poverty level and they tend to live in reservations or groups away from populated areas. Of course a city like Panama City which has nearly half of the countries population also has a lot more concentrated poverty, especially on the Colon side of the corridor.
There has been an increase of immigration into Panama over the last few years mostly coming from Colombia and other Latin American countries. Most are seeking better work opportunities or political asylum. According to an article I posted earlier in the year only 26,000 people applied for residency in Panama between January 2007 and March 2009. Of that number there were only about 2500 applications from North America.That is a very small proportion of the population.
With these facts in perspective lets compare this to what is happening in the U.S.. Since 1980 the United States has seen a 33% increase in population and most of it due to both legal and illegal immigration. If you look at the facts of this immigration it becomes obvious that this uncontrolled immigration is one of the reasons they have so many fiscal and growing cultural problems. The U.S. is becoming a very fragmented society because most of these immigrants never become part of the melting pot like they used to during the wave of immigration after the two world wars. Now they don't learn the language and place ever increasing burdens on the health and education systems. I stumbled on a great website that clearly tells the story of American immigration and how it has/is affecting the country. I encourage you to spend some time looking over this data. Unfortunately even if they stopped the huge flow of immigration the country will still grow at unprecedented levels due to what has taken place in the last 30 years.